Peptide Nanofibers Research Articles

Engineering supramolecular peptide nanofibers for in vivo platelet-hitchhiking beyond ligand-receptor recognition.

Ex vivo or in vivo cell-hitchhiking has emerged as a potential means for efficient drug delivery and various disease therapies. However, many challenges remain, such as the complicated engineering process and dependence on ligand-receptor interaction. Here, we present a simple in vivo platelet-hitchhiking strategy based on self-assembling peptides without ligand modification. The engineered peptide nanofibers can hitchhike ultrafast (<5 s) and efficiently on both resting and activated platelets in a receptor-independent and species-independent manner. Mechanistic studies showed that unique secondary structure of nanofibers, which lead to surface exposure of hydrophobic and hydrogen bond-forming groups, might primarily contribute to the selective and efficient platelet-hitchhiking behavior. After intravenous injection, these peptide nanofibers hitchhiked in situ on circulating platelets and achieved almost 20-fold lung accumulation. Our study provides not only a different paradigm of in vivo platelet-hitchhiking beyond ligand-receptor recognition but also a potential strategy for lung-targeted drug delivery and pulmonary disease therapy.

A TLR7 Agonist Conjugated to a Nanofibrous Peptide Hydrogel as a Potent Vaccine Adjuvant.

Toll-like receptors (TLRs) recognize pathogen- and damage-associated molecular patterns and, in turn, trigger the release of cytokines and other immunostimulatory molecules. As a result, TLR agonists are increasingly being investigated as vaccine adjuvants. Many of these agonists are small molecules that quickly diffuse away from the vaccination site, limiting their co-localization with antigens and, thus, their effect. Here, the small-molecule TLR7 agonist 1V209 is conjugated to a positively-charged multidomain peptide (MDP) hydrogel, K2, which was previously shown to act as an adjuvant promoting humoral immunity. Mixing the 1V209-conjugated K2 50:50 with the unfunctionalized K2 produces hydrogels that retain the shear-thinning and self-healing physical properties of the original MDP while improving the solubility of 1V209 more than 200-fold compared to the unconjugated molecule. When co-delivered with ovalbumin as a model antigen, 1V209-functionalized K2 produces a robust Th2 immune response and an antigen-specific Th1 immune response superior to alum, a widely used vaccine adjuvant. Together, these results suggest that K2 MDP hydrogels functionalized with 1V209 are a promising adjuvant for vaccines against infectious diseases, especially those benefiting from a combined Th1 and Th2 immune response.

Chaperone‐Derived Copper(I)‐Binding Peptide Nanofibers Disrupt Copper Homeostasis in Cancer Cells

Chaperone‐Derived Copper(I)‐Binding Peptide Nanofibers Disrupt Copper Homeostasis in Cancer Cells

Chaperone-Derived Copper(I)-Binding Peptide Nanofibers Disrupt Copper Homeostasis in Cancer Cells.

Copper (Cu) is a transition metal that plays crucial roles in cellular metabolism. Cu+ homeostasis is upregulated in many cancers and contributes to tumorigenesis. However, therapeutic strategies to target Cu+ homeostasis in cancer cells are rarely explored because small molecule Cu+ chelators have poor binding affinity in comparison to the intracellular Cu+ chaperones, enzymes, or ligands. To address this challenge, we introduce a Cu+ chaperone-inspired supramolecular approach to disrupt Cu+ homeostasis in cancer cells that induces programmed cell death. The Nap-FFMTCGGCR peptide self-assembles into nanofibers inside cancer cells with high binding affinity and selectivity for Cu+ due to the presence of the unique MT/CGGC motif, which is conserved in intracellular Cu+ chaperones. Nap-FFMTCGGCR exhibits cytotoxicity towards triple negative breast cancer cells (MDA-MB-231), impairs the activity of Cu+ dependent co-chaperone super oxide dismutase1 (SOD1), and induces oxidative stress. In contrast, Nap-FFMTCGGCR has minimal impact on normal HEK 293T cells. Control peptides show that the self-assembly and Cu+ binding must work in synergy to successfully disrupt Cu+ homeostasis. We show that assembly-enhanced affinity for metal ions opens new therapeutic strategies to address disease-relevant metal ion homeostasis.

PCL/soy peptide nanofibers incorporated with riboflavin/HP-β-CD assemblies for improving fruit storage quality

In this study, we first successfully developed functionalized electrospun nanofibers (PCL/SP/ICs) loaded with Riboflavin (RF) for fruit preservation with inclusion complexes (RF/HP-β-CD, IC) formed by encapsulating RF with hydroxypropyl-β-cyclodextrin (HP-β-CD) as a core material and soy peptide-assisted polycaprolactones (PCL/SP) as an overwrap material. Compared to 1 wt% and 5 wt% IC, nanofibers implanted with 3 wt% IC had an acceptable water contact angle (87.40°), good thermal stability, and superior mechanical properties. Also, RF/HP-β-CD integration conferred antimicrobial and antioxidant capabilities to PCL/SP fiber membranes. High-performance liquid chromatography (HPLC) studies revealed that produced films of PCL/SP/ICs could continuously and controllably release RF (within 200 h), hence retarding grape degradation and decreasing mass loss rate and titratable acid content throughout an 8-day storage period. Based on these findings, electrospun nanofiber films may be useful for vitamin loading in active food packaging.

Template-assisted Flexible-to-rigid Transition of Peptides in Head-to-tail Self-polymerization Enables Sequence-controllable and Post-modifiable Peptide Nanofibers.

Peptide-based nanofibers are promising materials for many essential applications and can be generalized into two categories, self-assembling peptide nanofibers (SAPNs) and poly(amino acid) nanofibers (PAANs). Non-covalent SAPNs are sequence-controllable, but poorly stable and not suitable for post-modification. While covalent PAANs are post-modifiable, however, their sequences are either monotonic or undefined. The nanofibers obtained by head-to-tail covalent coupling polymerization of sequence-known peptides, which we call series-connected peptide nanofibers (SCPNs), promise to have the advantages of both SAPNs and PAANs, but they are barely reported. The undesired backbiting effect during the head-to-tail polymerization is one of the possible challenges. Here, we present a template-assisted strategy to trigger the flexible-to-rigid transition of peptide units, which can avoid the backbiting effect and enable consecutive intermolecular polymerization of peptides to produce desired sequence-controlled covalent SCPNs. SCPNs are highly stable and can function as excellent parent materials for various post-processing to create diverse hierarchical materials independent of the peptide sequence. Moreover, SCPNs allow for the display of predetermined functional groups at regular intervals along the nanofibers by pre-modification of the initial peptide sequence. SCPNs represent a new category of peptide-based nanofibers with outstanding performances and vast potential.

Maneuvering the mineralization of self-assembled peptide nanofibers for designing mechanically-stiffened self-healable composites toward bone-mimetic ECM.

Extracellular matrix (ECM) elasticity remains a crucial parameter to determine cell-material interactions (viz. adhesion, growth, and differentiation), cellular communication, and migration that are essential to tissue repair and regeneration. Supramolecular peptide hydrogels with their 3-dimensional porous network and tuneable mechanical properties have emerged as an excellent class of ECM-mimetic biomaterials with relevant dynamic attributes and bioactivity. Here, we demonstrate the design of minimalist amyloid-inspired peptide amphiphiles, CnPA (n = 6, 8, 10, 12) with tuneable peptide nanostructures that are efficiently biomineralized and cross-linked using bioactive silicates. Such hydrogel composites, CnBG exhibit excellent mechanical attributes and possess excellent self-healing abilities and collagen-like strain-stiffening ability as desired for bone ECM mimetic scaffold. The composites exhibited the formation of a hydroxyapatite mineral phase upon incubation in a simulated body fluid that rendered mechanical stiffness akin to the hydroxyapatite-bridged collagen fibers to match the bone tissue elasticity eventually. In a nutshell, peptide nanostructure-guided temporal effects and mechanical attributes demonstrate C8BG to be an optimal composite. Finally, such constructs feature the potential for adhesion, proliferation of U2OS cells, high alkaline phosphatase activity, and osteoconductivity.

Neurophilic peptide-reinforced dual-fiber-network bioactive hydrogels for spinal cord injury repair

Spinal cord injury (SCI) is a challenging central nervous system disorder that characterized by microenvironmental disturbances following injury, which can be addressed by simulating the microenvironment of the spinal cord regeneration. Herein, we report the design and synthesis of bioactive hydrogels with a dual-fiber-network (DFN) porous structure, using self-assembled peptide nanofibers (PNFs) and natural cellulose nanofibers (CNFs). A neurophilic peptide is further introduced to enhance nervous regeneration capability of the pre-prepared PNF/CNF hydrogels, which then exhibit excellent neuro-affinity, self-healing ability, biodegradability, and biocompatibility, facilitating targeted SCI repair and regeneration through the hydrogel injection. The in vitro experiments reveal that the DFN hydrogel can enhance the proliferation and migration of bone marrow mesenchymal stem cells, and induce neural stem cell (NSC) proliferation with enhanced neuronal differentiation and axonal growth. Additionally, the in vivo studies validate that the hydrogel attenuates the post-SCI inflammation, inhibits reactive astrocyte proliferation, and facilitates endogenous NSC proliferation and migration, as well as promotes neuronal growth and axonal regeneration. The potential mechanism of SCI repair is ascribed to the hydrogel-induced activation of the PI3K/AKT/mTOR pathway, which alleviates inflammatory response, inhibits excessive reactive response of glial cells, and promotes NSC differentiation into neurons. This neurophilic peptide-reinforced DFN bioactive hydrogel system, with its comprehensive approach to SCI repair, holds great potential for clinical applications.

Scaffold loaded LPS-hUCMSC-sEVs promote Osteo/odontogenic differentiation and angiogenic potential of hDPSCs

ObjectiveThe formation of dentin-pulp complex determines the success of vital pulp therapy. Human umbilical cord mesenchymal stem cell-derived small extracellular vesicles (hUCMSC-sEVs) appeared to have stronger effect in anti-inflammatory and promoting the proliferation and migration of human dental pulp stem cells (hDPSCs). Moreover, Lipopolysaccharides (LPS) pretreatment can enhance the rapeutic potency of extracellular vesicles. LPS pretreatment hUCMSC-sEVs have the potential to regenerate the dentin-pulp complex by recruiting hDPSCs. This paper aims to develop collagen sponge/self-assembling peptide nanofiber scaffold (CS/SAPNS) composite scaffold loaded with LPS pretreatment hUCMSC-sEVs (CS/SAPNS-sEVs), and assess the release characteristics of hUCMSC-sEVs and the effect of this composite scaffold on osteo/odontogenic differentiation and angiogenic potential in hDPSCs. MethodsLPS pretreatment hUCMSC-sEVs (LPS-hUCMSC-sEVs) were mixed with self-assembling peptide hydrogel and loaded onto collagen sponge to obtain the CS/SAPNS-sEVs. BCA assay, nanoparticle analysis, transmission electron microscopy and laser confocal microscopy were used to investigate the characteristics of LPS-hUCMSC-sEVs loaded on CS/SAPNS. Osteo/odontogenic differentiation ability of hDPSCs were analyzed by ALP stainning, alizarin red staining. RT-PCR and Western blot analysis were performed to confirm the levels of osteo/odontogenic factors and angiogenic factors, and the involvement of NF-κB pathway was verified by immunocytochemical staining and Western blot analysis. ResultsCS/SAPNS could control LPS-hUCMSC-sEVs release for 7 days and keep their structural integrity. CS/SAPNS-sEVs promoted deposition of calcified nodules and expression of osteogenic/odontogenic and angiogenic factors in hDPSCs. On the contrary, inhibition of the NF-κB pathway down-regulated the expression of CS/SAPNS-sEVs-regulated osteo/odontogenic and angiogenic factors. ConclusionCS/SNAPS could be used as scaffold for LPS-hUCMSC-sEVs, and CS/SAPNS-sEVs may promote osteo/odontogenic differentiation and enhance the angiogenic potential of hDPSCs through activating the NF-κB pathway.

Co-assembling bioactive short peptide nanofibers coated silk scaffolds induce neurite outgrowth of PC12 cells

Controlling biomolecular-cell interactions is crucial for the design of scaffolds for tissue engineering (TE). Regenerated silk fibroin (RSF) has been extensively used as TE scaffolds, however, RSF showed poor attachment of neuronal cells, such as rat pheochromocytoma (PC12) cells. In this work, amphiphilic peptides containing a hydrophobic isoleucine tail (I3) and laminin or fibronectin derived peptides (IKVAV, PDSGR, YIGSR, RGDS and PHSRN) were designed for promoting scaffold-cell interaction. Three of them (I3KVAV, I3RGDS and I3YIGSR) can self-assemble into nanofibers, therefore, were used to enhance the application of RSF in neuron TE. Live / dead assays revealed that the peptides exhibited negligible cytotoxicity against PC12 cells. The specific interaction between PC12 cells and the peptides were investigate using atomic force microscopy (AFM). The results indicated a synergistic effect in the designed peptides, promoting cellular attachment, proliferation and morphology changes. In addition, AFM results showed that co-assembling peptides I3KVAV and I3YIGSR possesses the best regulation of proliferation and attachment of PC12 cells, consistent with immunofluorescence staining results. Moreover, cell culture with hydrogels revealed that a mixture of peptides I3KVAV and I3YIGSR can also promote 3D neurites outgrowth. The approach of combining two different self-assembling peptides shows great potential for nerve regeneration applications.

Anti-Cytokine Active Immunotherapy Based on Supramolecular Peptides for Alleviating IL-1β-Mediated Inflammation.

IL-1β is a principal proinflammatory cytokine underlying multiple local and systemic chronic inflammatory conditions including psoriasis, rheumatoid arthritis, inflammatory bowel disease, and type 2 diabetes. Passive immunotherapies and biologic drugs targeting IL-1β, while offering significant clinical benefit, nevertheless have limitations such as significant non-response rates, induction of anti-drug antibodies, and high costs. Here, an active immunotherapy raising antibody responses against IL-1β employing self-assembling peptide nanofibers is described. The nanofibers contain defined quantities of B-cell epitopes from IL-1β and exogenous T helper epitopes and employ the Q11 self-assembling peptide platform. Without adjuvant, the nanofibers raised durable anti-IL-1β antibody responses that inhibit IL-1β activity in vitro and in vivo. In a mouse model of imiquimod-induced psoriasis, prophylactic immunizations with the nanofibers diminished symptoms of epidermal thickening. This therapeutic effect is associated with biasing the immune response toward an anti-inflammatory IgG1/Th2 phenotype and a lowered expression of proinflammatory genes in the skin. Further, anti-IL-1β nanofibers induced therapeutic immunosuppressive CD62L+ Treg cells. This technology represents a potential alternative for passive immunotherapies and other biologics for treating chronic inflammatory conditions.

Injectable Self-Healing Antibacterial Hydrogels with Tailored Functions by Loading Peptide Nanofiber-Biomimetic Silver Nanoparticles.

Polymer hydrogels find extensive application in biomedicine, serving specific purposes such as drug delivery, biosensing, bioimaging, cancer therapy, tissue engineering, and others. In response to the growing threat of bacterial infections and the escalating resistance to conventional antibiotics, this research introduces a novel injectable, self-healing antimicrobial hydrogel comprising bioactive aldolized hyaluronic acid (AHA) and quaternized chitosan (QCS). This designed QCS/AHA hydrogel incorporates self-assembling peptide nanofibers (PNFs) and small-sized silver nanoparticles (AgNPs) for tailored functionality. The resulting hybrid QCS/AHA/PNF/AgNPs hydrogel demonstrates impressive rheological characteristics, broad-spectrum antimicrobial efficacy, and high biocompatibility. Notably, its antimicrobial effectiveness against Escherichia coli and S. aureus surpasses 99.9%, underscoring its potential for treating infectious wounds. Moreover, the rheological analysis confirms its excellent shear-thinning and self-healing properties, enabling it to conform closely to irregular wound surfaces. Furthermore, the cytotoxicity assessment reveals its compatibility with human umbilical vein endothelial cells, exhibiting no significant adverse effects. The combined attributes of this bioactive QCS/AHA/PNF/AgNPs hydrogel position it as a promising candidate for antimicrobial applications and wound healing.

Parallel β-Sheet Structure and Structural Heterogeneity Detected within Q11 Self-Assembling Peptide Nanofibers.

Q11 peptide nanofibers are used as a biomaterial for applications such as antigen presentation and tissue engineering, yet detailed knowledge of molecular-level structure has not been reported. The Q11 peptide sequence was designed using heuristics-based patterning of hydrophobic and polar amino acids with oppositely charged amino acids placed at opposite ends of the sequence to promote antiparallel β-sheet formation. In this work, we employed solid-state nuclear magnetic resonance spectroscopy (NMR) to evaluate whether the molecular organization within Q11 self-assembled peptide nanofibers is consistent with the expectations of the peptide designers. We discovered that Q11 forms a distribution of molecular structures. NMR data from two-dimensional (2D) 13C-13C dipolar-assisted rotational resonance indicate that the K3 and E9 residues between Q11 β-strands are spatially proximate (within ∼0.6 nm). Frequency-selective rotational echo double resonance (fsREDOR) on K3 Nζ and E9 Cδ-labeled sites showed that approximately 9% of the sites are close enough for salt bridge formation to occur. Surprisingly, dipolar recoupling measurements revealed that Q11 peptides do not assemble into antiparallel β-sheets as expected, and structural analysis using Fourier-transform infrared spectroscopy and 2D NMR alone can be misleading. 13C PITHIRDS-CT dipolar recoupling measurements showed that the most abundant structure consists of parallel β-sheets, in contrast to the expected antiparallel β-sheet structure. Structural heterogeneity was detected from 15N{13C} REDOR measurements, with approximately 22% of β-strands having antiparallel nearest neighbors. We cannot propose a complete structural model of Q11 nanofibers because of the complexity involved when examining structurally heterogeneous samples using NMR. Altogether, our results show that while heuristics-based patterning is effective in promoting β-sheet formation, designing a peptide sequence to form a targeted β-strand arrangement remains challenging.

Supramolecular Nanofibers Ameliorate Bleomycin-Induced Pulmonary Fibrosis by Restoring Autophagy.

Idiopathic pulmonary fibrosis (IPF) is a progressive and ultimately fatal interstitial lung disease, with limited therapeutic options available. Impaired autophagy resulting from aberrant TRB3/p62 protein-protein interactions (PPIs) contributes to the progression of IPF. Restoration of autophagy by modulating the TRB3/p62 PPIs has rarely been reported for the treatment of IPF. Herein, peptide nanofibers are developed that specifically bind to TRB3 protein and explored their potential as a therapeutic approach for IPF. By conjugating with the self-assembling fragment (Ac-GFFY), a TRB3-binding peptide motif A2 allows for the formation of nanofibers with a stable α-helix secondary structure. The resulting peptide (Ac-GFFY-A2) nanofibers exhibit specific high-affinity binding to TRB3 protein in saline buffer and better capacity of cellular uptake to A2 peptide. Furthermore, the TRB3-targeting peptide nanofibers efficiently interfere with the aberrant TRB3/p62 PPIs in activated fibroblasts and fibrotic lung tissue of mice, thereby restoring autophagy dysfunction. The TRB3-targeting peptide nanofibers inhibit myofibroblast differentiation, collagen production, and fibroblast migration in vitro is demonstrated, as well as bleomycin-induced pulmonary fibrosis in vivo. This study provides a supramolecular method to modulate PPIs and highlights a promising strategy for treating IPF diseases by restoring autophagy.

Tunable Macroscopic Alignment of Self-Assembling Peptide Nanofibers.

Progress in the design and synthesis of nanostructured self-assembling systems has facilitated the realization of numerous nanoscale geometries, including fibers, ribbons, and sheets. A key challenge has been achieving control across multiple length scales and creating macroscopic structures with nanoscale organization. Here, we present a facile extrusion-based fabrication method to produce anisotropic, nanofibrous hydrogels using self-assembling peptides. The application of shear force coinciding with ion-triggered gelation is used to kinetically trap supramolecular nanofibers into aligned, hierarchical macrostructures. Further, we demonstrate the ability to tune the nanostructure of macroscopic hydrogels through modulating phosphate buffer concentration during peptide self-assembly. In addition, increases in the nanostructural anisotropy of fabricated hydrogels are found to enhance their strength and stiffness under hydrated conditions. To demonstrate their utility as an extracellular matrix-mimetic biomaterial, aligned nanofibrous hydrogels are used to guide directional spreading of multiple cell types, but strikingly, increased matrix alignment is not always correlated with increased cellular alignment. Nanoscale observations reveal differences in cell-matrix interactions between variably aligned scaffolds and implicate the need for mechanical coupling for cells to understand nanofibrous alignment cues. In total, innovations in the supramolecular engineering of self-assembling peptides allow us to decouple nanostructure from macrostructure and generate a gradient of anisotropic nanofibrous hydrogels. We anticipate that control of architecture at multiple length scales will be critical for a variety of applications, including the bottom-up tissue engineering explored here.

Exploring Bimetallic Nanoparticles in Alzheimer's Therapy: A Novel Bio-Assisted Synthesis with Multitarget Potential.

Unlocking the potential of metal nanoparticles (NPs) in biomedical applications represents a leading endeavor in contemporary research. Among these, gold NPs (AuNPs) and silver NPs (AgNPs) have shown promising strides in combatting complex neurodegenerative ailments like Alzheimer's disease. Yet, the unexplored realm of bimetallic Au/Ag-NP harbors immense potential, concealing undiscovered opportunities for enhanced therapeutic effectiveness through the synergistic interaction of metal ions. Nonetheless, the limitations of traditional synthesis methods have restricted the preparation, biocompatibility, and versatility of these NPs, prompting an urgent requirement for innovative approaches. Biobased synthetic methodologies have emerged as a noteworthy solution to address these challenges. Our study ventures into uncharted terrain, harnessing collagen-mimicking peptide nanofibers as a bioactive template for the synthesis of bimetallic NPs. These green NPs exhibit remarkable activity in inhibiting amyloid β (Aβ) protein aggregation with almost 74% inhibition, surpassing the individual impacts of Au and Ag NPs, which show inhibition percentages of 66 and 43, respectively. The bimetallic Au/Ag-NPs not only demonstrate powerful inhibition of Aβ, but they also demonstrate inhibitory activity against esterase (∼50%) and against reactive oxygen species (ROS) (∼75%), metamorphosing into multifaceted therapeutic agents for Alzheimer's disease. Au/Ag-NPs have proven highly beneficial in surpassing cellular barriers, as evidenced by studies on tissue penetration, 3D uptake, and endosomal escape, and these attributes also hold promise for the future treatment modalities. The findings indicate that the intrinsic traits of Au/Ag-NPs provide numerous mechanistic benefits, such as inhibiting Aβ and acetylcholinesterase (AChE), and reducing stress related to ROS, in addition to their advantageous internalization properties. This research represents a notable advancement in the development of multitargeted treatments for neurodegenerative disorders using bimetallic NPs, diverging from the prevalent emphasis on AuNPs in the current literature.

Supramolecular Peptide Self-Assemblies Facilitate Oral Immunization.

Oral immunization is a promising strategy for preventing and treating gastrointestinal (GI) infections and diseases, as it allows for direct access to the disease site. To elicit immune responses within the GI tract, however, there are many obstacles that oral vaccines must surmount, including proteolytic degradation and thick mucus barriers. Here, we employed a modular self-assembling peptide nanofiber platform to facilitate oral immunization against both peptide and small molecule epitopes. Synthesizing nanofibers with d-amino acids rendered them resistant to proteases in vitro, whereas l-amino acid nanofibers were rapidly degraded. Additionally, the inclusion of peptide sequences rich in proline, alanine, and serine (PAS), increased nanofiber muco-penetration, and accelerated nanofiber transport through the GI tract. Oral immunization with PASylated nanofibers and mucosal adjuvant generated local and systemic immune responses to a peptide epitope but only for l-amino acid nanofibers. Further, we were able to apply this design to also enable oral immunization against a small molecule epitope and illustrated the therapeutic and prophylactic effectiveness of these immunizations in mouse models of colitis. These findings demonstrate that supramolecular peptide self-assemblies have promise as oral vaccines and immunotherapies.

Advancements in self-assembling peptides: Bridging gaps in 3D cell culture and electronic device fabrication.

Self-assembling peptides (SAPs) show promise in creating synthetic microenvironments that regulate cellular function and tissue repair. Also, the precise π-π interactions and hydrogen bonding within self-assembled peptide structures enable the creation of quantum confined structures, leading to reduced band gaps and the emergence of semiconductor properties within the superstructures. This review emphasizes the need for standardized 3D cell culture methods and electronic devices based on SAPs for monitoring cell communication and controlling cell surface morphology. Additionally, the gap in understanding the relationship between SAP peptide sequences and nanostructures is highlighted, underscoring the importance of optimizing peptide deposition parameters, which affect charge transport and bioactivity due to varying morphologies. The potential of peptide nanofibers as extracellular matrix mimics and the introduction of the zone casting method for improved film deposition are discussed within this review, aiming to bridge knowledge gaps and offer insights into fields like tissue engineering and materials science, with the potential for groundbreaking applications at the interface of biology and materials engineering.

Active immunotherapy for C5a-mediated inflammation using adjuvant-free self-assembled peptide nanofibers

The terminal protein in the complement cascade C5a is a potent inflammatory molecule and chemoattractant that is involved in the pathology of multiple inflammatory diseases including sepsis and arthritis, making it a promising protein to target with immunotherapies. Active immunotherapies, in which patients are immunized against problematic self-molecules and generate therapeutic antibodies as a result, have received increasing interest as an alternative to traditional monoclonal antibody treatments. In previous work, we have designed supramolecular self-assembling peptide nanofibers as active immunotherapies with defined combinations of B- and T-cell epitopes. Herein, the self-assembling peptide Q11 platform was employed to generate a C5a-targeting active immunotherapy. Two of three predicted B-cell epitope peptides from C5a were found to be immunogenic when displayed within Q11 nanofibers, and the nanofibers were capable of reducing C5a serum concentrations following immunization. Contrastingly, C5a's precursor protein C5 maintained its original concentration, promising to minimize side effects heretofore associated with C5-targeted therapies. Immunization protected mice against an LPS-challenge model of sepsis, and it reduced clinical severity in a model of collagen-antibody induced arthritis. Together, this work indicates the potential for targeting terminal complement proteins with active immunotherapies by leveraging the immunogenicity of self-assembled peptide nanomaterials. Statement of significanceChronic inflammatory diseases such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease are currently treated primarily with monoclonal antibodies against key inflammatory mediators. While helpful for many patients, they have high non-response rates, are costly, and commonly fail as anti-drug antibodies are raised by the patient. The approach we describe here explores a fundamentally different treatment paradigm: raising therapeutic antibody responses with an active immunotherapy.We employ innovative supramolecular peptide nanomaterials to elicit neutralizing antibody responses against complement component C5a and demonstrate therapeutic efficacy in preclinical mouse models of sepsis and rheumatoid arthritis. The strategy reported may represent a potential alternative to monoclonal antibody therapies.

Self-assembly of amphiphilic helical-coiled peptide nanofibers and inhibition of fibril formation with curcumin

Amphiphilic peptide sequences are conducive to secondary structures that self-assemble into higher-ordered peptide nanostructures. A select set of amphiphilic polycationic peptides displayed stable helical-coiled structures that self-assembled into peptide nanofibers. The progression of peptide fibril formation revealed short protofibrils that extended into thin filaments and into an entangled network of nanofibers over an extended (5 days) incubation period. Ligand binding with 8-anilinonaphthalene-1-sulfonic acid (ANS) and Congo Red (CR) confirmed the amphiphilic helical-coiled peptide structure assembly into nanofibers, whereas curcumin treatment led to inhibition of fibril formation. Considering the vast repertoire of fibrous biomaterials and peptide or protein (mis)folding contingent on fibril formation, this work relates the molecular interplay in between sequence composition, structural folding and the ligand binding events impacting peptide self-assembly into nanofibers.